Ratchet buckle for tightening strap



FIG. 1 is a top plan view showing my design for a ratchet buckle for tightening strap;

FIG. 2 is a side-elevational view thereof;

FIG. 3 is an end elevational view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a side-elevational view thereof taken from the side opposite to that shown in FIG. 2; and

FIG. 6 is an end elevational view thereof taken from the side opposite to that shown in FIG. 3. 

The ornamental design for a ratchet buckle for tightening strap, as shown. 